Squab, the term used for young pigeons is described as tasting quite a bit like "dark meat chicken", which would be appropriate as the meat itself is a very dark. Substituting the Cornish hen created a bit of an interesting dilemma. The broth and wine colored the skin of the bird grey. If I wasn't 100% convinced that the hen's I had purchased were fresh I would have been hesitant to serve them to my taste testers. I believe that any cook would run into this same issue. Some suggestions that were made to overcome this would be to cook the birds with the skin on and remove the skin prior to serving, or to bake the meat of your choice and serve it with a sauce made from the remaining ingredients. You won't get the same texture but who wants to eat rubbery skin??

stew (n.) - c. 1300, "vessel for cooking," from stew (v.). Later "heated room," especially for bathing (late 14c.). The meaning "stewed meat with vegetables" is first recorded 1756. The obsolete slang meaning "brothel" (mid-14c., usually plural, stews) is from a parallel sense of "public bath house" (mid-14c.), carried over from Old French estuve "bath, bath house; bawdy house," reflecting the reputation of medieval bath houses.

late 14c., transitive "to bathe (a person or a body part) in a steam bath," from Old French estuver "have a hot bath, plunge into a bath; stew" (Modern French étuver), of uncertain origin. Common Romanic (cognates: Spanish estufar, Italian stufare), possibly from Vulgar Latin *extufare "evaporate," from ex- "out" + *tufus "vapor, steam," from Greek typhos "smoke." Compare Old English stuf-bæþ "hot-air bath;" see stove.

Intransitive use from 1590s. Meaning "to boil slowly, to cook meat by simmering it in liquid" is attested from early 15c. The meaning "to be left to the consequences of one's actions" is from 1650s, especially in figurative expression to stew in one's own juices. Related: Stewed; stewing. Slang stewed "drunk" first attested 1737.

.xiiij. Quystis Scune.—Take a pece of beef or of mutoun, and wyne and fayre water, and caste in-to a potte, an late hem boyle, an skeme it wyl an clene; þan take quystes, an stoppe hem wyth-in wyth hole pepyr, and marwe, an þan caste hem in-to þe potte, an ceuere wyl þe potte, an let hem stere ryȝth wyl to-gederys; an þan take powder gyngere, and a lytel verious an salt, and caste þer-to, an þanne serue hem forth in a fayre dysshe, a quyste or to in a dysshe, in þe maner of a potage: an whan þowe shalt serue hem forth, take a lytil of þe broth, an put on dysshe wyth quystys, an serue forth.

xiiij - Quystis Scune. Take a pece of beef or of mutoun, and wyne and fayre water, and caste in-to a potte, an late hem boyle, an skeme it wyl an clene; than take quystes, an stoppe hem wyth-in wyth hole pepyr, and marwe, an than caste hem in-to the potte, an ceuere wyl the potte, an let hem stere ry3th wyl to-gederys; an than take powder gyngere, and a lytel verious an salt, and caste ther-to, an thanne serue hem forth in a fayre dysshe, a quyste or to in a dysshe, in the maner of a potage: an whan thowe shalt serue hem forth, take a lytil of the broth, an put on dysshe wyth quystys, an serue forth.

14. Pigeon Stewed - Take a piece of beef or of mutton, and wine and fair water, and caste into a pot, an let them boil, and skim it well and clean; then take pigeons, and stop them within with whole pepper, and marrow, and then cast them into the pot, an cover well the pot, and let them stir right well together; an then take powder ginger, and a little verjuice and salt, and cast thereto, and then serve them forth in a fair dish, a pigeon or two in a dish, in the manner of a potage: an when you shall serve them forth, take a little of the broth, and put on dish with pigeons, and serve forth.

Put all ingredients into a pot and bring it to a boil. Cook till the hen is tender and then serve.

As recipes go, this couldn't be simpler. I do plan on serving this at an event in the future. The taste testers enjoyed it, even though it very much resembled what it was, boiled Cornish game hen ("tastes just like chicken") in a very flavorful broth. You could thicken the broth using one of the period thickeners (bread, eggs or rice flour), and serve this with furmenty.

Quystes. Take a pese of befe or of motyn wyn & watyr boyle hit skeme hit clene than take quystes chop hem with yn with hole pepyr & cast hem in to the pott & let hem stew ryght well to gedyr & take poudyr of gynger & a lytyll vergeys & salt & cast ther to do hem in fayre dischys a quyst or ij in a disch for a maner of potage and when thu shalt serve hit forth take a lytyll broth & put hit in dischys to the quystys.

To mak quystis tak a pece of beef or of moton and wyne and water and boile it and scem it clene then stop the quistes within with whole peppur and cast them in a pot and cover it and let it stewe welle put ther to poudur of guinger watire and salt and cast ther to and put them in faire disches one or ij in a dische for a maner of potage and when they be serued furthe tak alitill brothe and put in the disches among the quystis and serue it.